Improvement in the construction of sheet-metal boilers



"lttitell glatte A. OBROWNELL, vor BROOKLYN, New YORK.

Letters Patent No. 91,903, (lated .Tune 29, 1869.

IMPROVEMENT IN THE CONSTRUCTION' OF SHEET-METAL BOILiElR-S.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom it may concern,.-

Be it known that I, A. C. BROWNELL, of B1ooklyn, Kings county, New York, have invented a new and useful Improvement in Copper Water-Boilers; and I do hereby declare that the following is a full, clear, and exactdescription thereof, which will' enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specification.

. Figure 1 is a side view`of my improved boiler, completed, parts being broken away-to show the construction.

Figure 2 is a longitudinal section oi a part of the same, partially formed, illustrating the manner of construction.

Figure 3 is a cross-section of the same, taken through the line a: x, iig. 2.

Similar letters of reference indicate corresponding parts.

My invention relates to water-boilers, or distributing-reservoirs, and has for its object to improve the construction of the same.

It consists principally in forming both heads domeshaped, and securing them to the body by doublesearning, riveting, or brazing. y

To accomplish this object, the bodylis dividedinto two halves, transversely, and the domeLheads doubleseamed, riveted, or brazed thereto, respectively. -These two halves are then double-seamed together, by intro-yy ducing a ring, or band, to serve as a mandrel within one of the heads, and forming the lseam over the Same.

The mandrel, or ring remains within. the boiler, a-nd serves to strengthen the boiler and prevent its collapsing. i Heretofore, boilers have been made with one head donble-seamed, but it .has been found impossible to unite two dome-heads to the body in this manner,v

because, after double-seaming one head to the body, there are no means for introducing a mandrel within the boiler,upon which mandrel the double seam `must be formed. 'lhe second lhead was therefore applied in a flat form, without double seaming, and frequently would be pressed from the body'by the weight of the water within the boiler.

The invention also consists in beading the double seams `of the heads longitudinally, in such a m'anner that the seam shall form part of the bead, thereby strengthening the latter, and imparting a neat and finished appearance thereto.

The seam is, as it were, swallowed up in the bead,

yand the point of connection nearly or entirely hidden from4 observation. V Ithas heretofore been customary to bead the body of a boiler at right angles to the seam, the latter extending longitudinally ofthe body, to unite its two sides to form a cylinder, but this beading forms simply 4an ornament for the heads, without alecting that portion of the seam lying between the heads. It serves simply as an ornament, and produces no strengthening effect whatever upon the seam.

A is the body of the boiler, to the end-edges of which the edges of the dome-shaped heads B are secured, by double seams, as shown in fig. 2.`

The parts of the boiler in which the said scams are formed are then beaded, as shown in iig. l, which beadin a not onl strengthens the boiler but also g1 a y a: 2

presses down the seam so that it is no longer discernible.

To enable this to be done, I make the body A, of the boilerin two parts, the line of division being at or near its centre.

The edge of' the one part is then bent out at right angles, and the edge of 'the other part is bent twice at right angles, as shown in fig. 2, preparatory to double-seaming the said parts together.

A.. strong iron wheel, or band, O, is then inserted in the one part, in such a way as to support the edges ofthe two parts when put together, and :serve as a .mandrel in forming the ldouble seam, by which said edges are connected to each other.

The wheel G may be made with cross-bars, or

spokes, c', as shown in iig. 3, or it may be made s o heavy as not to require such strengthening. The seams may then 'be sweatedand soldered, and the. mid- .dle seam may be covered with a ring-cap, a2, neatly soldered to the sides of the body A, as shown in iig. 1, so as to give to said, band the appearance of `beading, as shown.

By this construction, -I am able to produce a distributing hot7water boiler with a dome-head upon each end, and double-seanied together in all its parts. This construction also enables the heads of the boiler to be secured to the body by riveting or by brazing.

The usual ingress, egress, and circulating-pipes are connected with the boiler in the ordinary inanner.

I claim as new, and desire to secure by Letters Patent- 1. The improved water-boiler, with both heads deine-shaped, double-seamed, brazed, or riveted tol the ends of its body, either with or without beading,

substantially as herein shown and described, for the` purpose speciled.

2. The body of a hotwater boiler, made in two parts, douhle-seamed=-to each other, and doubleseamed, brazed, or riveted to the domc-hcads, substantially as herein shown and described, for the purpose specified. A.

3. The heavy wneel, or band, C, whether mede` each other, substantially in the manner herein shown and described, and for the purpose set forth.

with or without spokes, or cross-bars, in combination l with the body A, of the boiler, at the point where the parts of suid'body are seemed to each other, substantially as herein shown and described, and for the purpose set forth.

4.- Beading sheet-metal boilers, end other articles longitudinally with thel double sean1s,inelndiug the szune, by which the parts of seid articles are secured to rlhe above specification of nie, vthis 15th day of Februar Witnesses:

E. GREENE COLLINS, JAuEs T. GRAHAM.

my invention signed by ly, 1869. A. C. BROWNELL. 

